Question

The power delivered to a single phase inductive load is measured with a dynamometer type wattmeter using a potential transformer (PT) of turns ratio 200:1 and the current transformer (CT) of turns ratio 1 : 5. Assume both the transformers to be ideal. The power factor of the load is 0.8. If the wattmeter reading is 200 W, then the apparent power of the load in kVA is

• A. 250

Answer 1

The correct option is A 250
As both the transformer are ideal the apparent power in KVA will be

$\frac{V}{200}\times \frac{I}{5}\times cos\varphi =200W$

$\Rightarrow VI=\frac{200\times 200\times 5}{0.8}=250KVA$